Method and apparatus for increasing fluid movement around oil well tools



J. A. ZUBLIN March 2, 1937.

METHOD AND APPARATUS FOR INCREASING FLUID MOVEMENT AROUND OIL WELL'TOOLS 3 sneets sheet 1 Filed Aug. 15, 1955 3 John A. Zublz'n WWW J. A. ZUBLIN March 2, 1937.

METHOD AND APPARATUS FOR INCREASING FLUID MOVEMENT AROUND OIL WELL TOOLS 5 Sheets-Sheet 2 Filed Aug. 15, 1935 IAIII John AZublz'n ZZT March 2, 1937. J. A. ZUBLIN METHOD AND APPARATUS FOR INCREASING FLUID MOVEMENT AROUND OIL WELL TOOLS Filed Aug. 15, 1935 5 Sheets-Sheet 3 3mm John A. Zufilz'n ii: "I," i O Patented Mar. 2, 1937 PATENT OFFICE METHOD AND APPARATUS FOR INCREAS- ING FLUID WELL TOOLS MOVEMENT AROUND OIL John A. Zublin, Los Angeles, Calif.

Application August 15, 1935, Serial No. 36,267

13 Claims.

The present invention is concerned with oil well tools of the rotary type which are used in conjunction with circulation fluid that is pumped down into the well through a string of drill pipe to bring to the ground surface cuttings and particles of soil, and it is more particularly concerned with means for increasing the movement of the fluid about and in the vicinity of the tool down in the well. As will be seen from the ensuing description, my invehtion may be applied to several types of tools, though it is described most fully in connection with drill bits because of its particular application thereto, and it is felt that a full description of one application will make obvious the application to other tools.

In general, rotary tools are operated in conjunction with fluid circulation as the fluid serves to remove sand, cuttings, and debris from the well after the tool has loosened the material. In

0 the case of drill bits, circulation is for the puring tool. Obviously the value derived from the circulation is dependent upon the agitation or movement of the fluid around the tool.

The usual circulation system in a well, hereinafter called the primary circulation, involves downward movement of the fluid inside the drill pipe and the upward movement outside the drill pipe, but such circulation is general in its direction and isnot as eflicient as it should be in that locality where the particles are to be picked up i by the fluid. The circulation from the drill pipe is normally discharged exteriorly of the tool and into the well fluid surrounding the tool. The usual result is the creation of relatively high velocity currents of small cross section which fail to move the biggest bulk of the fluid, leaving a large part of the well fluid moving too slowly to be effective in cleaning the hole by removing particles of dirt around the tool.

Consequently it is found that cuttings are not removed as fast as formed, so thatdrilling is impeded by the bit working in a mass of large cuttings. In soft or clayey formations these large pieces can be broken up and dissolved in the fluid if the fluid is agitated sufliciently', but the present circulation system does not agitate the fluid sumciently to distintegrate and dissolve the pieces as fat as they are cut by the bit. This dissolving can be accomplished by moving all the well fluid more violently, and by so circulating the fluid that these pieces of relatively hard substances are driven against the sides and bottom of the well to break them up. The impact of hard particles also aids drilling by removing the formation.

Thus it becomes a general object of my inven tion to increase the amount of movement of the well fluid in the vicinity of the tool so that the entire well fluid is moving at sufllcient velocity to pick up cuttings and keep the well clean for drilling.

It is also an object of my invention to secure better and widespread distribution of the fluid movement so that all parts 01' the hole in the vicinity of the tool are reached and cleaned, and the tool is washed clean of accumulations of cuttings that would ball'it up.

It is another object to move all the well fluid in a definite circulation which agitates and churns the cuttings to hasten their dissolution in the well fluid, and which impels large solid pieces of relatively hard substances against the walls of the well bore to assist the drilling, both by breaking up the pieces and by removing additional formation as the pieces strike the hole sides.

It is a further object or the invention to effect a strong movement of a larger volume of fluid,

.amounting, in a given time,to several times the volume that is circulated through the drill pipe, the additional circulation being effected by and in addition to the drill pipe circulation.

And a further object is to create a local circulation so that the sides of the hole, casing, or the like, can be washed clean of accumulated sand, dirt, refuse, or other undesirable substances, and so that there will be carried into and retained within the tool samples of formation, or foreign particles that cannot be disintegrated, these retained pieces being removed from the well with the tool.

These objects are achieved according to my invention by discharging the circulation fluid from the drill pipe through a nozzle to form a jet, and using the jet to create a secondary or local circulation that moves a relatively large volume of well fluid around the tool, the how being from the bottom of the tool up to some point above the nozzle and return downwardly. This local circulation exists in addition to the primary circulation between the ground surface and the tool. Thus the energy-from a source outside the well and carried bythe' primary circulation is utilized to create a local circulation contained entirely within the well.

The means used to carry out this method varies with the type of tool, but in general includes a fluid passage formed as a part of the tool or as an addition thereto, and a nozzle jetting the primary circulation fluid into the fluid passage which is open to the well at points above and below the nozzle. The jet creates a circulation of the well fluid through the fluid passage and discharges with the jet fluid.

How the above and other objects and advantages of my invention are attained will be more easily understood from the following description and the annexed drawings, in which:

Fig. l is a vertical median section through a blade type drill bit embodying my invention;

Fig. 2 is an elevation of the bit of Fig. 1;

Fig. 3 is a bottom view of Fig. 2;

Fig. 4 is a side elevation of a flshtail type drill bit embodying my invention;

Fig. 5 is a vertical median section through i Fig. 6 is a vertical median section of a gymtory type drill bit embodying my invention;

Fig. 'l is a view similar to Fig. 6 showing a variational design of fluid passages;

Fig. 8 is a vertical median section of a roller type drill bit;

Fig. 9 is a vertical median section through a blade type drill bit embodying myinvention;

Fig. 10 is a bottom view of Fig. 9;

Fig. 11 is a vertical section through a core drill embodying my invention;

Fig. 12 is a vertical median section through a disc type drill bit embodying my invention;

Fig. 13 is a vertical section through a well tool whichm beused asabailerorflshingtool;

Fig. 14 is a vertical section showing a flshtail bit with a detachable coupling, embodying my invention;

Fig. 15 is a vertical section or a bit with an extendedbodytoincreasethedistancebetween the fluid inlet and outlet; and

Fig. 16 is a vertical section of a cleaning tool in a section of perforated casing.

There is shown in Fig. 1 a sectional view through a blade type bit having a body 2. provided with a plurality of cutting blades II and reaming blades 22. The upper end of the body is provided with a threaded pin 23 for attach 0 ment of the bit to astring of drill pipe, not

shown, from which it receives circulation fluid. This fluid passes through nozzle 24 which is here shown as a detachable sleeve in order that the nozzle may be easily replaced when worn, although it will be understood that nozzle 24 may be formed as an integral part of bit body 20.

The bit body is formed with an internal fluid passage, generally indicated at 25, which opens to the well at its upper end through one or more inlet ports 26 through which the passage receives well fluid, and the passage also opens at its lower end to discharge fluid through outlet "a into the well. Preferably, though not necessarily, passage 25 is constricted as at 21 to form a throat which receives the Jet of circulation fluid discharged from nozzle 2|.

The stream of circulation fluid issuing from nozzle 24 forms a jet which, as it passes through throat 21, creates a zone of relatively lower, pressure, in accordance with well known laws of hydraulics, and fluid is drawn into passage 25 v through ports 26 from the well space surrounding the bit. This well liquid intimately mingles with the jet liquid and the combined liquids are discharged through the lower end of the fluid passage at the bottom of the well. As this combined liquid, now well liquid, rises within the well and outside of the bit body, it passes ports 28 and a large portion of this liquid will again be drawn into the ports 26 and will recirculate downwardly within the fluid passage.

The primary circulation extends between the ground surface and the tool, passing through the drill pipe and tool, and the length of well occupied thereby. Ihere is now added a local or secondary circulation, indicated by arrows 23. which is the same in direction as the primary circulation but which is confined locally to the vicinity of the tool. The energy of the jet is suflicient to create, in addition to the primary circulation indicated by arrows 29a, this sec- .Ondary or local circulation of well fluid through the fluid passage, and the volume of well fluid so circulated in a given length of time amounts to several times the volume of fluid issuing from nozzle 23. The result is that there is a very great increase in the fluid movement around the bit and not only is the velocity of substantially all the fluid increased to a point where it will pick up cuttings and wash the blades clean, thus rendering the drill bit more effective, but the movement of the fluid is so widespread that all surrounding parts of the well are reached and there are no pockets or dead spots where cuttings can accumulate.

The secondary circulation very thoroughly mixes the fluid around the tool and picks up the harder cuttings, as well as harder foreign particles, to carry them along in the stream. 'Ihese cuttings are circulated through the tool and are driven downwardly against the cutting elements of the bit or the sides or bottom of the well where the impact breaks them up and they help dislodge uncut formation. Disintegration and dissolution of the pieces is facilitated by the churning of the fluid induced by the secondary circulation which, by its violent motion, is much better for this purpose than the more quiet primary circulation.

As illustrative of the breadth of my invention and the various arrangements and constructions of parts that may be made, I show in Figs. 4 to 16 the application of the invention to various types of OH well tools. Fig. 4 shows the application of the invention to a flshtail type bit comprising a body generally indicated at 32 and having a threaded pin 33 adapting'the bit for attachment to a drill pipe. Circulation fluid is received into the bit through passage 34 in the upper portion, the pasage dividing at its lower end so that the fluid is discharged through both of two jets 35. The two water passages 33 into which nozzles 35 discharge are formed one'on each side of the bit blade by means of the two semi-cylindrical housings 31 which form a part of the bit body. With this construction, each jet draws well fluid into its associated water passage 36 through the'upper inlet 33 and discharges it at the lower end outlet 33 of the passage so that there is created on each side of the blade a separate localized circulation which moves in the manner already described. The primary and secondary circulations are indicated respectively by the dotted and solid arrows.

It will be obvious from the construction illustrated in Figs. 4 and 5 that the conventional type of flshtail bit may be readily adapted to my invention by the addition of nozzles 35 to the conventional water passages and the addition of housings 31.

Figs. 6 and 7 show the adaptation of my invention to a gyratory bit of the type generally known as the Zublin" bit. This bit comprises a body 4| having rotatably mounted upon its lower end a cutter 42 and adapted at its upper end for attachment to a drill pipe in the manner already described. Fluid passage 43 opens at one side of the body through port 44 to receive well fluid and the fluid passage is divided at its lower end, a portion of the fluid being discharged at45 beneath the cutter and the remainder being discharged at 48 above and to one side of the cutter where the discharge is particularly effective in washing clean the blades oi. the cutter. The primary circulation fluid is discharged through nozzle 41 into the fluid passage 43 at a point below port 44 but above the division of the fluid passage into its two, terminal portions.

Fig. '7 shows the same type of bit with a variational construction of the water passages. In this construction the bit is provided with a primary circulation passage 48 through which a portion of the circulation fluid received item the drill pipe is conveyed directly, under into passage 430. through nozzle 41a which takes from the main circulation passage 48 a portion of the circulation fluid and jets it into passage 43a to form the secondary circulation, as already described. In both of the forms shown in Figs. 6 and 7 a portion of the fluid issuing through ports will pass upwardly and be drawn into ports 44 for circulation locally about the tool.

There are shown in Figs. 8 and 12 other types of bits with rotatable cutters. The bit of Fig. 8 has a large central fluid passage 5| opening to the well through side ports 52 and discharging at its lower end at 55 above and around the rotatable cutters. Primary circulation fluid is received in the bit through passage 54 at the upper end of the bit and discharged to passage 5i through nozzle 55, to set up secondary circulation around the tool in the manner previously described.

It will be noticed that the bit body is here made in two parts, the lower part 56 carrying the rotatable cutters, and being similar to conventional construction, except that the fluid passage is somewhat enlarged. The upper portion 51 of the body contains the well fluid inlets 52 and the nozzle 55 for jetting the circulation fluid into the internal fluid passage. Where the over-all length of the tool or hit would otherwise be too great, this two-piece construction may be adopted, the upper section being in the nature of an extension of the lower portion of the bit body. This construction also has the further advantage that the upper portion 5! alone may be used as a converter to adapt my invention to a conventional type of bit, by adding portion 51 to the standard bit.

The general body construction illustrated in Fig. 8'may be equipped with'any one of a number of types of rotatable cutters. For example, there is shown in Fig. 12 a one-piece body 59 supplied with cutting discs 68.

The two-piece body construction may be also used in a blade or drag type bit as well as with the other types, such a blade bit being illustrated in Fig. 9. The lower body section 6| a is provided with a pair of digging blades, as may best be seen in Fig. 10. Within body 61a is a fluid passage 62 communicating with a similar passage in upper body portion 8 lb which is provided with well fluid inlet 83 and nozzle 84 for introducing primary circulation fluid. The two fluid streams entering through inlets 83 and 64 mingle in passage 62 and are discharged at the lower end of said passage at .55 around the cutting blades of the bit, this fluid rising around the bit and a portion of the combined fluids again circulating through the internal fluid passage. Passage 62 may be of uniform section as shown, or. be formed with a constricted throat as in Fi 1.

How my invention may be applied to a core drill is illustrated in Fig. 11. In general the core drill may be of any conventional type, and is here shown as comprising the usual inner core-receiving barrel 68, outer barrel 69, and cutter head Ill. The outer barrel is connected to coupling I5 which is provided with a fluid passage Ii into which the primary circulation fluid enters through nozzle 12. After being discharged from the lower end of passage H, the fluid moves downwardly in the annular space between the inner and outer core barrels, being finally introduced into the well through ports 13. The coupling 15 has one or more inlet ports 14 which admit well fluid at the upper end of passage II so that there may be established, in the manner already described, a

local circulation of fluid downwardly inside the core drill and upwardly outside the drill.

There is illustrated in Fig. 13 a tool which may be used as a bailer or sample taker to remove large particles of cuttings, iron, or other substances from the well. Body I8 is provided with an internal fluid passage 19, and in the lower portion of that passage there is placed a coarse screen 88 or other suitable device which will retain the larger particles of solid matter entering through inlet ports 83 and passing downwardly through fluid passage 19. Primary circulation fluid enters the tool through passage 8! and is discharged into passage 18 through nozzle 82. The pieces retained in the bit may be pieces of formation which it is desired to examine to determine the geological structure, or they may be iron or other foreign material that cannot be disintegrated.

Fig. 14 illustrates a tool whichcomprises a conventional flshtail bit 85 and a coupling 88 which is used where it is desired to convey a portion of the circulation fluid directly to the bit and to extend the local circulation to some point above the bit. Primary circulation fluid enters the tool through passage 8'! and a portion of this fluid is conveyed, under relatively high pressure, through coupling 86 down to the discharge passages in bit 85. A portion of this primary circulation fluid is diverted from passage 85 and discharges from nozzle 88 into a second fluid passage 89 into which the well fluid is drawn through ports -98 by action of the jet leaving nozzle 88. These combined fluids issue from passage 88 at outlet 9| and circulate upwardly about the tool.

In the event that it is desired to extend the localized circulation over a greater length of the well bore than may be reached by a bit body or coupling of ordinary length, there may be used a drilling tool made up of several pieces as illustrated in Fig. 15. Here the entire tool comprises a drill bit 93 and a coupling 94 connected by a piece of drill pipe 95 which may be of any desired length. These three pieces all combine to provide the tool with an internal fluid passage 96 receiving well fluid through one or more ports 91 and drcuiation fluid through music ll, discharge of thefluldsbeinghadatthelowerend ltaoi'passage aroundthe cuttingelementsof the bit. With this drilling tool circulation is 5 established in a manner as previously ducribed, but the distance between the inlet and outlet endsof lihasbeenextendedsoasto establish the local circulation over a greater length of well than heretofore shown.

Fig. 16 illustrates a cleaning tool for washing aperforatedcasing llofreeofsandanddirt lodged in the perforations. The tool comprises a body formed with a fluid e "I which receivm the primary circulation as a jet from nonale III. The e has one or more ports I openingatthesideofthe'tooltothecasinginterior. 'Ihetoolbodyisofsuchdiameterboth above and below ports III that the body flts snuglywithincasing illil. Thefluidisuingfromthe bottom of n; III is forced out of the casing through the perforations and rises around the casingtobedrawnintoports iflbyagainpassing through the casing perforations, establishing the secondary circulation indicated by arrows Ill. The primary circulation, indicated by arrows I5, is also maintained, since a part of the well fluid will be forced up outside the casing so that it enters again through perforations above ports I ll. maintained,- while the secondary circulation washes clean the casing perforations. The tool israisedandloweredthroughthe casingtoclean its entire length.

From the foregoing, it will be clear that the varlous modified forms of my invention described can be combined in other ways than illustrated by the drawings. Hence, the drawings and description are to be considered as illustrative of rather 40 than restrictive upon my invention as set forth in the appended claims.

I claim as my invention: 1. The method of increasing the movement of liquid-around an oil well tool continuously re- 45 ceiving circulation liquid flowing downwardly from the ground surface through a string of drill pipe and returning upwardly to the groimd surfacethroughtheannularspacebetweenwelland drill pipe, that includes adding a simultaneous 50 local circulation of liquid entering the tool from said annular space and moving downwardly through the tool to return around and outside the tool in said annular space.

2. The method of increasing the movement of 5 liquid around an oil well tool continuously re ceiving circulation liquid flowing downwardly fromthegroundsurfacethroughastringofdrill pipeandreturningupwardlytothegmundsurfaoethroughtheannularspacebetweenwell and drill pipe, that includes the liquid fromthedrillpipeinajetlocatedwithinaliquid passagewithinthebodyofthetooLandutilizing theiettoestablisharoundthetoolalocalcircu-' laflon ofwellliquid drawn hytheietfrom outside thetoolintothelimiidpassageand thelk uidi'mmsaidplsllgctothetooiexterior. 3.'lhemethodofinaeaslngthemovementof liquidaroundanoilwelltoolcontinuouslyreceivingcirculation liquidinaprimarycirculation 7 flowing downwardly from the ground surface throughastringofdrlllllbcandrehirningupwardlytothegroundmrfaeethmughtheannular spacebetweenwellanddrillpipe,thatincludes the liquidfromthedrillpipeina jeeandutilillngthelettoestablishasimub A continuous supply of fluid is taneous local circulation of well liquid around the tool which continuously recirculates portions of both the well liquid drawn into the tool from outside it and the jet liquid in a path that coincides with the primary circulation, as it discharges from the tool and passes over cutting elements on the tool.

4. The method of circulating liquid around an oil well tool on the end of a string of drill pipe, that includes maintaining a continuous primary circulation of drilling liquid flowing from the ground surface down through the drill pipe and tool and returning within the well outside the drill pipe and tool, and creating by the primary circulation a simultaneous secondary local circulation of drilling liquid entering the tool from the well space outside the tool and flowing downwardly through the tool only then returning upwardly outside the tool.

5. The method of increasing the movement of liquid around an oil well tool continuously receiving circulation liquid flowing downwardly from the ground surface through a string of drill pipe and returning upwardly to the ground surface through the annular space between well and drill pipe, that includes adding a local liquid circulation in the vicinity of the tool that circulates relatively hard solid particles through the tool, retaining a portion at least of the particles within the tool, and withdrawing the retained particles with the tool.

6. A rotary oil well tool adapted for attachment to a string of drill pipe from which the tool receives a continuous supply of circulation fluid, comprising a body, an interior fluid passage in the body open at its upper and lower ends to the well space outside the tool, and a nozzle receiving circulation fluid from the drill pipe and discharging such fluid into the interior passage in a jet that draws well fluid from outside the tool into the inlet end of the passage for circulation through the passage.

7. A rotary oil well tool adapted for attachment to a string of drill pipe from which the tool receives a continuous supply of circulation fluid, comprising a body, an interior fluid passage in the body open at its upper and lower ends to the well space outside the tool, and a nozzle receiving circulation fluid from the drill pipe and discharging such fluid into the interior passage in a jet that draws well fluid from outside the tool into the upper inlet end of the passage for circulation through the passage, the nozzle being located in the passage below the inlet and above the outlet.

8. A rotary oil well tool adapted for attachment to a string of drill pipe from which the tool receives a continuous supply of circulation fluid, comprising a body, an interior fluid passage in the body open at its upper and lower ends to the well space outside the tool, and a nozzle receiving circulation fluid from the drill pipe and such fluid into the interior passage in a jet that draws well fluid from outside the tool into the upper inlet end of the passage for circulation through the passage, the interior fluid e being constricted at a point intermediate its ends and below the nozzle.

9. A rotary well drilling bit adapted for attachment to a string of drill pipe from which the tool receives a continuous supply of circulation fluid, comprising a body, a plurality of fixed cutter blades on the lower end of the body, a central streamlined fluid e in the body open at its upper and lower ends to the well space outside the tool, and a nozzle receiving circulation fluid from the drill pipe and discharging such fluid into the interior passage in a jet that draws well fluid from outside the tool into the upper inlet end of the passage for circulation through the passage and outwardly around the cutter blades.

10. A rotary well drilling bit adapted for attachment to a string of drill pipe from which the tool receives a continuous supply of circulation fluid, comprising a body, a plurality of fixed cutter blades on the lower end of the body, a central streamlined fluid passage in the body open at its upper and lower ends to the well space outside the tool, and a nozzle receiving circulation fluid from the drill pipe and discharging such fluid into the interior passage in a jet that draws well fluid from outside the tool into the upper inlet end of the passage for circulation through the passage and outwardly around the cutter blades, the interior fluid passage being constricted at a point intermediate its ends and below the nozzle.

11. In a rotary drill bit having a body adapted for attachment to a string of drill pipe from which the bit receives a continuous supply of circulation fluid, a cutter rotatably mounted on the lower end of the body, a. fluid passage within the body open at its upper and lower ends direct- 1y to the well space outside the bit, and a nozzle receiving circulation fluid from the drill pipe and discharging such fluid into the passage in a jet that draws well fluid from outside the bit into the upper inlet end of the passage for circulation through the passage.

12. In a rotary drill bit having a body adapted for attachment to a string of drill pipe from which the bit receives a continuous supply of circulation fluid, a cutter rotatably mounted on the lower end of the body, a fluid passage within the body open at its upper and lower ends directly to the well space outside the bit, and a nozzle receiving circulation fluid from the drill pipe and discharging such fluid into the passage in a jet that draws well fluid from outside the bit into the upper inlet end of the passage for circulation through the passage, said passage discharging above and eccentrically of the axis of revolution of the rotating cutter.

13. A rotary oil well tool adapted for attachment to a string of drill pipe from which the tool receives a continuous supply of circulation fluid, comprising a body, an interior fluid passage in the body open at its upper and lower ends to the well space outside the tool, and a nozzle receiving circulation fluid from the drill pipe and discharging such fluid into the interior passage in a jet that draws well fluid from outside the tool into the upper inlet end of the passage for circulation through the passage, and a second fluid passage within the body receiving fluid from the drill pipe and discharging it to the tool exterior near the bottom of the tool without going through the nozzle.

JOHN A. ZUBLIN. 

